Cooling towers are used to cool liquid by contact with air. Many cooling towers are of the counter-flow type, in which the warm liquid is allowed to flow downwardly through the tower and a counter current flow of air is drawn by various means upward through the falling liquid to cool the liquid. Other designs utilize a cross-flow of air, and forced air systems. A common application for liquid cooling towers is for cooling water to dissipate waste heat in electrical generating and process plants and industrial and institutional air-conditioning systems.
Most cooling towers include a tower or frame structure. This structural assembly is provided to support dead and live loads, including air moving equipment such as a fan, motor, gearbox, drive shaft or coupling, liquid distribution equipment, such as distribution headers and spray nozzles, and heat transfer surface media such as a fill assembly. The fill assembly material generally has spaces through which the liquid flows downwardly and the air flows upwardly to provide heat and mass transfer between the liquid and the air. Different types of fill materials, e.g., stacked layers of open-celled clay tiles, are commercially available, depending on the desired design and operating characteristics.
Due to the corrosive nature of the air and water drawn through such cooling towers, it has been the past practice to either assemble such cooling towers of stainless steel or galvanized and coated metal, or for larger field-erected towers, to construct such cooling towers of wood, which is chemically treated under pressure, or concrete at least for the structural parts of the tower, or combination of these materials.
These cooling towers are generally categorized as either field-erected (constructed on site) or factory-assembled/packaged units (constructed at a factory and transported to the site). Typically, for packaged units, each unit is a single cell (self-contained, with separate collecting basin, fill, fluid distribution system, input/output, fan, etc.) and multiple cells may be grouped together to form a larger overall cooling tower.
Within the last twenty years or so, prior art solutions began using fiber reinforced plastic (FRP) beams and columns including those shown in U.S. Pat. No. 7,275,734 to Bland (2007), which is incorporated herein by reference, for larger field-erected cooling towers. For smaller factory-assembled units, the support structures may utilize metal or FRP components, or combination of both. However, the smaller single cell units include exterior panels constructed from metal (e.g., stainless/galvanized metal), which require bolts or screws for fastening together. The apparent hole(s) necessary for these fastening types result in the potential for leaks from the interior to the exterior—which is undesirable.
As such, a need exists for a factory-assembled single cell cooling tower unit having exterior fiber reinforced plastic panels fastened using no, or relatively few, conventional bolts or screws. Accordingly, such a cooling tower having exterior panels using screwless and boltless fastening means is desired. Such a construction reduces or eliminates the potential for leaks and/or the need for applying waterproofing materials around the fasteners.